Hmm. Things are not going so well now. I lost two continues trying to kill the boss that looks like Blanka from Street Fighter II, and so have made it to Level 5 with just two lives (and no more continues, it seems) left.
I then had a go on Versus Mode on Xbox Live. Sadly, it is totally broken. If you host, you win. The reason? If you’re not hosting, all of your movements are delayed by almost a second, making it impossible to beat all but the worst opponents.